Fraction-collecting apparatus



NOV. 12, 1968 MlTCHELL 3,410,321

FRACT ION COLLECT ING APPARATUS Filed July 8, 1965 s Sheets-Sheet 1 E 1.N W" 68 'T 9 9 NOV. 12, 1968 MITCHELL 3,410,321

FRACTION-COLLECTING APPARATUS Filed July 8, 1965 3 Sheets-Sheet 2 N v-12, 1 D. F. MITCHELL FRACT ION COLLECT ING APPARATUS 5 Sheets-Sheet 5Filed July 8, 1965 United States Patent 3,410,321 FRACTION-COLLECTINGAPPARATUS David F. Mitchell, Tewksbury, Mass., assignor t0 InternationalEquipment Company, Needham, Mass., a corporation of Massachusetts FiledJuly 8, 1965, Ser. No. 470,399 14 Claims. (Cl. 141-130) ABSTRACT OF THEDISCLOSURE Fraction-collecting apparatus provided with a support to holda specimen-containing tube vertically, the bottom of the tube beingcapable of being punctured without fracturing, a conduit having a needlefor puncturing the bottom of the tube and supported in verticalalignment with the axis of the tube, a backing member engageable withthe open end of the tube, and means to effect relative vertical movementbetween the needle and the container to effect the puncturing of thetube. The apparatus also including means to refrigerate the tube and toenable it to be used with tubes of different dimensions. The apparatusalso provides backing members that are closures, the closures alsohaving conduits.

withdrawal of such amounts through the open end of the tubes isdiflicult to perform and usually results in some mixing of the gradientswhich is, of course, objectionable.

The problem has been recognized for some time and special tubes havebeen proposed having an axial passage in their bottom, closed by a sealthat could be punctured by the needle of a hypodermic or like syringe bywhich small amounts could then be withdrawn. Such tubes, were, ofcourse, relatively expensive as compared with plastic tubes now commonlyused in centrifuges. The thinner walled plastic tubes can be piercedwith a needle of the hypodermic type but such needles are subject tobecoming plugged in so doing. By way of example, tubes of cellulosenitrate and cellulose butyrate are available in wall thicknesses rangingfrom ten to fifteen thousandths of an inch. The walls of polypropyleneand polycarbonate tubes are considerably thicker, forty thousandths ofan inch, for example. Special needles are required with said thickerwalled tubes.

The objective of the present inventions is to provide apparatus in whicha specimen tube of any material that can have a hole punctured in itsbottom without fracturing can be mounted, its bottom pierced by aneedle, and the flow of the gradients from the specimen-containing tubeto the collection tubes controlled easily and accurately.

In accordance with the invention, this objective is attained withapparatus utilizing, at least when set up for use, a specimen containerincluding an open-ended tube portion for a liquid separated intogradients and a closure portion for its open end provided with a conduitin communication with the interior of the tube portion. The apparatusincludes means to support the container in a vertical position, bottomend downwardly, a conduit including a tubular pointed needle of a stocksufficiently rigid to withstand pressures required to force the needlethrough the bottom of the tube portion, and means supporting the needlein a vertical position with its puncturing point disposed upwardlytowards the bottom of the tube portion and in axial alinement therewithwith the needle. The apparatus also includes means to effect relativemovement between the two supporting means to effect the puncturing ofthe bottom of the tube portion by the needle. One of the conduits is anoutlet conduit and has a discharge end and the other conduit is an inletconduit and means are provided to control the flow of fluid from thespecimen container to the collecting tubes.

Another objective is to provide such apparatus with a seal againstleakage, the seal being pierced by the needle and on the relativemovement between the supporting means to efiect puncturing of the bottomof the specimen-containing tube, the bottom being seated against theseal.

Another objective of the invention is to provide a conveyor for thecollecting tubes movable relative to the station defined by thedischarge end of the outlet conduit.

Another objective of the invention is to provide apparatus including abase and an upright with the con- -veyor being a turntable rotatablysupported thereby and with the container and needle supporting meansmounted on the upright.

A further objective of the invention is to provide the apparatus with arefrigerant chamber and additional important objectives include means bywhich the chamber and the tube supporting means are easily adapted tospecimen containers of different dimensions.

Yet another objective of the invenetion is the pro vision of a needleensuring ready penetration of the bottom of the specimen containing tubeeven when thick walled.

In the accompanying drawings, there are shown embodiments of theinvention illustrative of these and other of its objectives, novelfeatures, and advantages.

In the drawings:

FIGURE 1 is a partly sectioned side view of apparatus in accordance withone embodiment of the invention,

FIGURE 2 is a section taken approximately along the indicated lines 2-2of FIGURE 1,

FIGURE 3 is a side elevational view of a tube piercing needle,

FIGURE 4 is a fragmentary view of the tube piercing end of the needleshowing the inlet,

FIGURE 5 is a like view of the tube piercing end turned from its FIGURE4 position,

FIGURE 6 is a section taken; approximately along the indicated lines 6-6of FIGURE 5,

FIGURE 7 is a fragmentary view of the apparatus with the tube holder andrefrigerant chamber adapted for a differently dimensioned tube,

FIGURE 8 is a fragmentary section, on a substantially increased scale,of the lower end of a tube end of the tube-puncturing needleillustrating means for controlling the relationship of the needle inletwith reference to the interior of a tube,

FIGURE 9 is a section taken approximately along the indicated lines 9-9of FIGURE 1, and

FIGURE 10 is a section taken approximately along the indicated lines10-10 of FIGURE 1.

The apparatus illustrated by FIGURES 1-9 of the drawings consists of abase 15 having an upwardly opening socket 16 to receive the lower end ofthe post or upright 17 and provided with a set screw 18 for detachablysecuring it therein. The post 17 has a collar 19 in support of thegenerally indicated turntable 20.

The turntable 20 is shown as consisting of an upper disc 21, a bottomdisc 22, and an intermediate disc 23.

The discs have central apertures freely receiving the post 17, theapertures being designated by the suffix addition A to the appropriatedisc-identifying reference numeral. The discs are interconnected invertically spaced relationship as by bolts 24 extending downwardlythrough the discs 21, 22, and 23. Each bolt 24 extends through tubularspacers 25 and 26, the spacers 25 being between the discs 21 and 23 andthe spacers 26 being between the discs 22 and 23.

The discs 21 and 23 have, adjacent their peripheries, a series ofuniformly spaced, vertically alined holes 21B and 23B, respectively,dimensioned to slidably receive collecting tubes 27 with their bottomends being supported by the bottom disc 22.

A collar 28, above the turntable 20 and secured to the post 17, as by aset screw 29 is provided with a radial arm 30 having an upturned end 31provided with a holder 32 for the outlet 33 to which one end of thedrain tube 34 is connected. On the undersurface of the arm 30, there isa downwardly opening cup 35 retaining a ball 36 backed by a spring 37.The disc 21 has a series of holes 210, one for each tube-receiving hole21B and in radial alinement therewith with the resulting detent actionpermitting the turntable to be indexed relative to the stationestablished by the discharge end of the outlet 33.

Spaced above the collar 28, there is a collar 38 rotatably supporting atransverse shaft 29 provided with a shaft-turning handle 40 and a pinion41 meshing with the vertical rack 42 anchored in a slot 43 in the post17. The post 17 is provided with a ring 44 below the slot 43 providing astop against which the collar 38 is seated by a spring 45 backed by theanchor ring 46 fixed to the post 17. The collar 38 has a set screw 47,see FIGURE 10, by which it may be locked to the post 17 in any elevatedposition, within the limits permitted by the rack and pinionconnections, against the returning action of the spring 45. The collar38 also has a radially disposed arm 48 provided with an upwardly openingsocket 49 provided with a set screw 50 and a concentric downwardlyopening passage 51.

A needle, generally indicated at 52, is shown in FIG- URES 36 and 10, asconsisting of a cannula 53 pro vided with a centrally located hub 54.The bottom piercing end of the cannula 53 is provided with a point 55 ofthe type so positioning the inlet 56 that it opens laterally. Thepiercing end also has two flattened zones 55A providing a V-shaped ridgeterminating in the point 55. In addition, the cannula 53 is shown ashaving a tapered portion 57 so reducing the diameter of the cannula thatthe maximum width, thereof, as measured across the inlet, is less thanthe diameter of the main part of the cannula. While other types ofneedles may be used, particularly with the thinner-walled tubes and withtubes having rubber seals, a needle of the type just described has theadvantages of enabling the bottoms of thicker-walled tubes to be readilypierced and of cutting a flap in them and other tubes, as it pierces thetube bottom, and pushing that flap away from the needle point in a zoneopposite its inlet 56. Such a flap is indicated at F in FIGURE 7.

The needle 52 is supported in the socket 49, pointed end upwardly andwith its other end extending downwardly through the passage 50 with theother end of the drain tube 34 connected thereto. The set screw 50serves to lock the hub securely in the socket 49 and the needle 52pierces a seal 59 shown as seated in the upper end thereof.

Adjacent the upper end of the post 17 there is a collar 60 detachablylocked thereto as by the set screw 61. The collar 60 has a radial arm 62having clamping jaws 62A adapted to be drawn together by the screw 63.The jaws 62A are shown in FIGURE 1 as supporting a holder 64 having adownwardly opening socket 65 having a seal '66 seated therein and aconcentric upwardly opening passage 67 to which the conduit 68 isattached and adapted to be opened and closed as by the clamp 69. Thesocket 65 is dimensioned to snugly receive and support the open endportion of a specimen containing tube 70 with its lower end positionedabove the needle 52 but axially alined therewith.

With a specimen-containing tube 70 and the needle 62 thus supported, andwith the clamp 69 closed, the handle 40 is swung by the technicianthereby to raise the needle 62 until it pierces the bottom of the tube70 and the tube bottom is seated on the seal 59. The desired fractioncan then be delivered to the collecting tube 27 at the collectingstation by releasing the clamp 69, the flow rate being slow, usually bydrops.

With the apparatus thus described, it will be assumed that the desiredfraction is determined by drop-counting and after that amount isdelivered, the clamp is then engaged and the turntable 20 is indexed tobring another collecting tube 27 into the station.

It will be appreciated that the specimen containing tubes vary as totheir dimensions. Their outside diameter, their length, or both mayvary. While the supporting means therefor are vertically adjustable, itshould be noted that it is a common requirement that specimencontainingtubes be maintained at or below a certain temperature.

For that reason, there is shown a collar 71 locked to the post 17 as bya set screw 72. The collar 71 includes a refrigerant holder 73 having athreaded and internally shouldered opening 74 in its bottom wall. Theopening 74 is dimensioned and threaded to receive the generallyindicated tube receiver 75 and a seal S. The receiver has a base 76provided with a sleeve 77 and having an opening 78 concentricallythereof. The sleeve 77 is dimensioned to receive a major part of thelength of the tube 70 when supported by the base 76 with its bottomexposed through the opening 78 for puncturing engagement by the needle62. It will be apparent from FIGURE 1 that the distance between thesocket 65 and the end of the sleeve 76 is desirably small.

With a tube of a smaller outside diameter, the tube 70A, for example,see FIGURE 7, it may be assumed that its length will be dilferent thanthat of the tube 70. The tube 70A cannot, accordingly, be properlysupported in the apparatus as thus far disclosed. The receiver 75 isaccordingly removed and replaced by the receiver 75A which may be of thesame construction as the receiver 75 and its corresponding parts are,accordingly, disr, tinguished by the sufiix addition A. The sleeve 77Ahas its inside diameter such as to snugly fit the tube 70A andpreferably has its outside diameter reduced so as to avoid unduethickness for the sake of thermal conductivity. The tube 70A is alsoshorter so that it is necessary to replace the holder 64 with a holder64A which may be of the same construction and has its correspondingparts distinguished by the suffix addition A, the socket 65A being of acorrespondingly smaller inside diameter and the holder beingproportioned to protrude downwardly a greater distance thereby tooverlie the open end of the tube 70A close to the upper end of thesleeve 77A.

It will also be noted that the container and refrigerant holding meansare removable from the post -17 and are adapted to have their positionsthereon vertically adjusted as desired or required.

It will also be noted that it will often be necessary or desirable tomaintain the temperature of the tubes 27 at or below a predeterminedtemperature during the period they are carried by the turntable 20. Forthat reason, see FIGURE 1, a refrigerant chamber 79 is mounted on theupright 17 to be supported by the socket 16 with the turntable 20 freeto rotate within it.

It should also be noted that specimen containers of the same dimensionsmay present additional problems. A container 70B of the same generaldimensions as the container 70 might have, by way of example, a lesserwall thickness or it might be that it was desirable to have the needle62 extend to a greater or lesser extent therein. For such reasons, itmay be desirable to provide the seal 59 with additional layers 59A, thenumber of which may be increased or decreased to vary needle penetrationas desired.

While the apparatus affords substantial advantages Whether the deliveryto each collecting container 27 is determined by the manual counting ofthe number of drops or by the technician timing the flow interval, theapparatus is adapted to a Wide range of control bases includingautomatic operation with automatic operator including the stepping ofthe turntable, the control of the volume, and the control of thedisplacement fluid, or any of them. In this connection, it will beapparent that with a replacement liquid delivered by a precision pump,the tube puncturing needle may be in the inlet conduit with the outletconduit in communication with the interior of the specimen tube via itsupper end.

By these or like means, the apparatus may be made operable to controlthe accurate delivery of fractions from a specimen containersuccessively to a series of collecting tubes.

I claim:

1. A tube-puncturing device for use with a specimen container in theform of an open-ended tube, at least the bottom portion of said tubebeing capable of being punctured by a needle, said apparatus comprisinga vertical support, means detachably supporting said tube, bottom enddownwardly exposed and with the tube axis vertical, said means includinga seat member for centering said tube, a backing member for holding theopen end of said tube against said seat, one of said members including aportion shaped and dimensioned to center and hold vertically a portionof a seated tube that is above said seat, and adjustable means operableto enable one of said members to be moved in a vertical directiontowards the other member to provide holding engagement of said backingmember with the open end of said seated tube, a conduit including atubular, pointed needle below said seat member and of stock sufficientlyrigid to withstand pressures required to force the needle through thebottom of the tube, means supporting said needle with the needle axisvertical and in alignment with the tube axis, both of said supportingmeans being mounted 0n said support, and means to elTect relativevertical movement between said two supporting means to eitect thepuncturing of said tube bottom by said needle.

2. The tube-puncturing device of claim 1 in which the means effectingvertical movement between the two supporting means includes a verticalportion of the support in the form of a rack and the needle supportingmeans includes a pinion meshing with the rack portion.

3. The tube-puncturing device of claim 2 and a spring yieldably opposingrelative movement of the needle supporting means towards the tubesupporting means and means to lock said needle supporting means to thesupport against the action of the spring.

4. The tube-puncturing device of claim 1 in which the support is a postand a turntable is axially mounted on said post and is provided with aplurality of equally spaced means for holding fraction collecting tubesin an upwardly opening position, said conduit being positioned todischarge into appropriate ones of the fraction collecting tubes as theturntable is turned.

5. The tube-puncturing device of claim 4 and a chamber for a refrigerantin which the turntable is located.

6. The tube-puncturing device of claim 1 in which there is an annularrefrigerant chamber, and the member centering and holding vertical aportion of a seated tube is the inner wall of the refrigerant chamber.

7. The tube-puncting device of claim 1 in which the seat member includesa threaded part and the member centering and holding vertical the seatedtube is threaded into the threaded seat part.

8. The tube-puncturing device of claim 1 in which the backing member isa closure including an inlet conduit in communication with the interiorof the tube.

9. The tube-puncturing device of claim 1 in which the backing member isthe member centering the tube and holding it vertical.

10. The tube-puncturing device of claim 9 in which the backing memberhas a downwardly opening socket dimensioned to snugly receive the openend of the seated tube.

11. The tube-puncturing device of claim 9 in which the backing memberincludes a tube-engaging adapter part and a supporting part having anaperture detachably receiving the adapater part, one of said partsincluding an annular shoulder holding the adapter part against upwardmovement.

12. The tube-puncturing device of claim 1 in which the backing member isthe vertically adjustable member.

13. A tube-puncturing device for use with a specimen container in theform of an open-ended tube, at least the bottom portion of said tubebeing capable of being punctured by a needle, said device comprisingmeans to support said tube, bottom end downwardly and exposed and withthe tube axis vertical, a conduit including a needle, said needle beinga cannula comprising a main portion and a tube-piercing portion taperinginwardly from its junction with said main portion and including a pointwhose apex is within the cylindrical boundary defined by the maincannula portion and which has a laterally opening inlet between saidapex and said junction, means supporting said needle with its pointupwardly and with the needle in axial alignment with the axis of a tubein said supporting means and means to effect relative vertical movementbetween the tube supporting means and the needle supporting means toefiect the puncturing of the tube bottom by said needle and the seatingof its tapered portion below said opening against said tube bottom.

14. The tube-puncturing device of claim 13 and means to adjust theposition of the tube supporting means rel ative to the needle supportingmeans independently of the means eifective relative movementtherebetween.

References Cited UNITED STATES PATENTS 931,297 8/1909 Handy et al.141--82 X 1,937,582 12/1933 Murray 2514 X 2,570,787 10/1951 Gammeter141329 X 2,604,249 7/1952 Gorham 141--130 FOREIGN PATENTS 1,323,7313/1953 France.

360,554 2/ 1922 Germany.

325,376 2/ 1930 Great Britain.

553,615 12/1956 Italy.

HOUSTON S. BELL, IR. Primary Examiner.

